Add error check to scenario outline, add java snippet escaping for + and .

core/src/main/java/cucumber/runtime/model/CucumberScenarioOutline.java

@@ -1,5 +1,6 @@
 package cucumber.runtime.model;
 
+import cucumber.runtime.CucumberException;
 import cucumber.runtime.Runtime;
 import gherkin.formatter.Formatter;
 import gherkin.formatter.Reporter;
@@ -103,13 +104,17 @@ private static DocString docStringWithTokensReplaced(DocString docString, List<S
     }
 
     private static String replaceTokens(Set<Integer> matchedColumns, List<String> headerCells, List<String> exampleCells, String text) {
-        for (int i = 0; i < headerCells.size(); i++) {
-            String headerCell = headerCells.get(i);
-            String value = exampleCells.get(i);
+        for (int col = 0; col < headerCells.size(); col++) {
+            String headerCell = headerCells.get(col);
+            String value = exampleCells.get(col);
             String token = "<" + headerCell + ">";
+
             if (text.contains(token)) {
                 text = text.replace(token, value);
-                matchedColumns.add(i);
+                if (text.isEmpty()) {
+                    throw new CucumberException("Step generated from scenario outline '" + token + "' is empty");
+                }
+                matchedColumns.add(col);
             }
         }
         return text;

core/src/main/java/cucumber/runtime/snippets/SnippetGenerator.java

@@ -24,6 +24,8 @@ public class SnippetGenerator {
             Pattern.compile("\\]"),
             Pattern.compile("\\?"),
             Pattern.compile("\\*"),
+            Pattern.compile("\\+"),
+            Pattern.compile("\\."),
             Pattern.compile("\\^"),};
 
     private static final String REGEXP_HINT = "Express the Regexp above with the code you wish you had";

core/src/main/java/cucumber/runtime/snippets/UnderscoreFunctionNameSanitizer.java

@@ -7,6 +7,9 @@ public String sanitizeFunctionName(String functionName) {
         StringBuilder sanitized = new StringBuilder();
 
         String trimmedFunctionName = functionName.trim();
+        if (trimmedFunctionName.isEmpty()) {
+            throw new IllegalArgumentException("Cannot have empty function name");
+        }
 
         sanitized.append(Character.isJavaIdentifierStart(trimmedFunctionName.charAt(0)) ? trimmedFunctionName.charAt(0) : SUBST);
         for (int i = 1; i < trimmedFunctionName.length(); i++) {

core/src/test/java/cucumber/runtime/snippets/UnderscoreFunctionNameSanitizerTest.java

@@ -0,0 +1,20 @@
+package cucumber.runtime.snippets;
+
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+
+public class UnderscoreFunctionNameSanitizerTest {
+
+    private UnderscoreFunctionNameSanitizer sanitizer = new UnderscoreFunctionNameSanitizer();
+
+    @Test
+    public void testSanitizeFunctionName() {
+        assertEquals("_test_function_123", sanitizer.sanitizeFunctionName(".test function 123 "));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testSanitizeEmptyFunctionName() {
+        sanitizer.sanitizeFunctionName("");
+    }
+
+}

java/src/test/java/cucumber/runtime/java/JavaSnippetTest.java

@@ -90,12 +90,12 @@ public void generatesSnippetWithEscapedQuestionMarks() {
     @Test
     public void generatesSnippetWithLotsOfEscapes() {
         String expected = "" +
-                "@Given(\"^\\\\^\\\\(\\\\[a-z\\\\]\\\\*\\\\)\\\\?\\\\$$\")\n" +
+                "@Given(\"^\\\\^\\\\(\\\\[a-z\\\\]\\\\*\\\\)\\\\?\\\\.\\\\+\\\\$$\")\n" +
                 "public void _a_z_$() throws Throwable {\n" +
                 "    // Express the Regexp above with the code you wish you had\n" +
                 "    throw new PendingException();\n" +
                 "}\n";
-        assertEquals(expected, snippetFor("^([a-z]*)?$"));
+        assertEquals(expected, snippetFor("^([a-z]*)?.+$"));
     }
 
     @Test